A US regulatory agency said Tuesday it would look into acquisitions made by five Big Tech firms over the past decade -- opening the door for potential antitrust reviews.

The bombshell announcement by the US Federal Trade Commission opens the door to possible investigations of deals made by Amazon, Apple, Facebook, Microsoft and Google parent Alphabet since 2010.

The FTC said in a statement it ordered the five firms "to provide information about prior acquisitions not reported to the antitrust agencies" between January 1, 2010 and December 31, 2019.

The move comes amid growing scrutiny of tech platforms which have dominated key economic sectors, and calls by some activists and politicians to break up the Silicon Valley giants.

Acquisitions by Big Tech firms as far back as 2010 will be reviewed by the US Federal Trade Commission for antitrust implications
Acquisitions by Big Tech firms as far back as 2010 will be reviewed by the US Federal Trade Commission for antitrust implications AFP / DENIS CHARLET

Antitrust experts have debated the legal and practical issues of attempting to "unwind" past acquisitions.

The FTC, one of the regulatory agencies that conducts antitrust reviews, said it would examine whether some of the deals "might have raised competitive concerns."

"This initiative will enable the Commission to take a closer look at acquisitions in this important sector, and also to evaluate whether the federal agencies are getting adequate notice of transactions that might harm competition," said FTC chairman Joe Simons.

The US Justice Department has already said it is reviewing potential anticompetitive actions by major tech platforms, and attorneys general from the majority of US states have launched antitrust investigations of Google and Facebook.

The actions come against a growing "techlash" reflecting declining public trust in big online firms, and fines levied against Facebook and Google over privacy violations.

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